click a4j button via javascript does not work

[Wolfgang]

Hi,

I tried to click a a4j:commandButton via javascript. It works all fine 
if I use a t:commandButton with the
attribute forceId="true". Is there a similar attribute for the 
a4j:commandButton available?

<h:selectOneMenu id="itemPosPicr"
                                rendered="#{currentData.renderedPicrPos}"
                                
valueChangeListener="#{siteChanger.valueChangePosPicrResult}"
                                onchange="valueChangePicr()">
                   <f:selectItems value="#{currentData.itemPosPicr}"/>
               </h:selectOneMenu>

           

               <script type="text/javascript" language="javascript">
                    function valueChangePicr() { 
document.getElementById("valueChangePicrButton").click(); }
               </script>

               <t:commandButton forceId="true" id="valueChangePicrButton"
                                style="display:none"
                                
actionListener="#{siteChanger.changePagePicr}"
                                styleClass="searchButton"/>
 

           <a4j:commandButton immediate="true" id="valueChangePicrButton"/>


Cheers!